In conventional cable television (CATV) systems, the outer conductor of a coaxial cable is electrically bonded to earth ground, i.e., grounded, at every end-user's home. This grounding is typically accomplished using a device called a bonding block or ground block. The bonding/ground block is usually located outside the home near the electrical service entry. Bonding is achieved by attaching the coaxial cable to the bonding block and attaching a wire from the electrical service ground to the bonding block. Because residential bonding blocks are usually outside the home, they are exposed to the elements such as rain, salt, sunlight, temperature extremes, and other harsh conditions. Since bonding blocks are primarily used as safety devices, it is imperative that they maintain a quality bond between the outer conductor of the coaxial cable and earth ground under these conditions.
Most existing ground blocks are made of inferior materials such as aluminum or zinc and corrode very quickly. Some are made of stainless steel but are constructed in such a way as to allow moisture to penetrate the interface between the coaxial cable and the bonding block, thus degrading the television signal and causing corrosion at the interface unless a weather seal is used.
Moreover, conventional metallic bonding/ground blocks typically use a set screw or a threading clamping mechanism to capture a first end of the grounding wire and to secure the grounding wire to the bonding/ground block for a long term, low contact resistant mechanical connection. The second end of the grounding wire is typically attached to a form of common bonding/grounding point at the point of installation, which may be, for example, private, residential, commercial, or contractual in nature. The second end is typically attached to the common bonding/grounding point by removing the outer covering to a recommended length, thus exposing the bare metallic wire for attachment. The attachment is typically achieved using a clamping device or a set screw that secures the wire to the bonding/grounding point for a low contact resistant mechanically sound connection. An exemplary ground block is illustrated in FIGS. 1 and 2, which is described in U.S. Pat. No. 7,462,042, the disclosure of which is incorporated herein by reference.
With conventional bonding/ground blocks, problems occur when an installer does not properly and/or sufficiently tighten the set screw or clamping device of the bonding/ground block, thus increasing the contact resistance and leading to a possible total disconnect. Increased contact resistance or total disconnect would cause the internal wiring of the installation to not be properly grounded or bonded to the remainder of the wiring at the installation location. Improper grounding/bonding could lead to RF ingress/egress of unwanted signals or, in the case of a lightning strike or electrical surge, to property damage, personal injury, or even death.
Accordingly, there is a need to overcome, or otherwise lessen the effects of, the disadvantages and shortcomings described above. Hence a need exists for an improved bonding/ground block that ensures a long term, low contact resistant mechanical connection and reliable electrical ground.